Watch bearing



J. F. BRUN ET AL WATCH BEARING Filed June 5 INVENTORS M El...

1 ATTORNEYS Patented Jan. 27, 1925 UNITED STATES PATENT OFF-ICE.

JOSEPH FRANQOIS BRUN AND PAUL ALBERT BRUN, OF NEW YORK, N. Y.

WATCH BEARING.

Application filed June 5,

To all whom it may concern.

Be it known that we, Josnrrr FRANQOIS BRUN and PAUL ALBERT BRUN, citizens of Switzerland, and residents of the borough of Manhattan, in the city and State of New York, have invented new and useful lVatch Bearings, of which the following is a specificationf This invention relates to watch construction and, more particularly, to that portion of the watch which serves as a bearing for the balance staff or pivot.

An object of the invention is to provide means for permitting the cap jewel which acts as an end or thrust bearing for the balance staff or pivot to move axially within its immediate confining element so as to allow for a corresponding movement of the bal ance staff or pivot when the watch is subjected to a sudden blow or jar, thereby obviating, to a great extent, breaking or bending of said balance staff or pivot.

Another object consists in providing means for performing the function just stated, which means can be applied to any watch of ordinary or standard construction without necessitating alteration of the balance bridge.

A further object consists in providing certain improvements in the form, construction and arrangement of the several parts, whereby the above named and other objects may be effectively attained.

A practical embodiment of our invention is represented in the accompanying drawin s, in whichig. 1 represents a detail top plan view of that portion of a watch mechanism designed to embody the invention.

Fig. 2 represents a section taken in the plane of the line IIII of Fig. 1, looking in the direction of the arrows; certain parts being shown in different positions in full and dotted lines.

The balance bridge of the watch is denoted by 1 and within it is fixed a jewel 2 which is bored, as indicated at 3, to provide a journal for the end of the balance staff or pivot 4.

This jewel 2 may conveniently be fixed in place by upsetting the surrounding edges of the bridge 1, above and below the jewel 2, as indicated, for instance, at 5.

On the upper part of the bridge 1 there is located a suitable plate 6, which may be removably secured to the bridge by means of 1924. Serial No. 718,002.

screws 7, 8 that pass through holes 9, 10 in the bridge and are threaded into holes 11, 12 in the plate 6.

The said plate 6 has a central opening 13 which is axially coincident with the opening in the bridge 1 in which the jewel 2 is con fined, and a cap jewel 14 is set in said opening 13 so as to rest upon one face of the jewel 2 and abut the end of the balance staff or pivot 4.

The upper wall of the aperture 18 is flared outwardly and upwardly, as indicated at 15, and a concave disk spring 16, composed of sheet metal or other suitable material, is fitted to rest on said flared surface 15, and is held in place by upsetting the surrounding upper edge of the plate 6 as indicated, for example, at 17.

The said spring 16 has a central aperture 18 which is fitted to receive the central portion of the convex upper end of the cap jewel 1 1, as indicated at- 19.

The tension of the spring 16 is normally downward so that it yieldingly urges the cap jewel 1 1 against the end of the balance staff or pivot 4 and against the upper surface of the jewel. 2.

It will be observed that there is a slight allowance for side motion or play of the cap jewel let within the opening 13, but the aperture 18 in the spring 16 cooperates with the convex upper end of the cap jewel 14 to normally hold the latter centrally within the opening 13.

Thus, the arrangement is such that the function of the spring is to normally and simultaneously hold the cap jewel in its lowermost and central position; but it is important to note that the surrounding wall of the opening 13 positively prevents any substantial lateral movement of the cap jewel away from its central position.

In operation, when the watch receives any shock which places a strain upon the balance staff or pivot 4, the same may yield in a longitudinal direction by forcing the cap jewel upwardly against the tension of the spring, as indicated in dotted lines in Fig. 2. This capacity for yielding tends greatly to prevent bending or breaking of the balance staff or pivot; and, as soon as the force of the blow or jar is spent, the spring will force the cap jewel and balance staff or pivot back to normal position.

From the foregoing description, it will be seen that our invention may be applied may be resorted to in the form, construe,

tion and arrangement of the several parts Without departing from the spirit and scope of: our inventionyand hence, Wedo notintend to be limited to the. details herein shown: anddescribed, except as they may be included in the claims.

iWhat :We claim is 2- comprising an operating pivot, a cap jewel engagingthe endo'f saidpivot ahons1ng. v I

151K131 alinement withsaid p vot. he character described immediately surrounding the cap jewel and wa=-spring fixedagainst bodily movement in saidhousing and normally urging the cap jewel. against the'pi-vot, whereby the .cap ijewelljis permitted to-yield axiallyin its housing under pressure exerted by said -52. Apparatus of the character described spring carried by said housing and normal- 1y urging the cap jewel-against the pivot,

whereby the cap jewel is permitted to yield axially in its housing; under pressure exerted by said pivot, said spring having a central 7 lhApp-aratus of-the characterv described,

the capjewel against the pivot, whereby the cap jewel is permitted to yield laterally in its housing ;,u1 ider pressure zierted [said pivot,1said spring. having (a. central aperture and saidscap jewelYhaVing conyexiipper end directly mating with said aperture, whereby the capjewel is. normally heldin e Apparatusofj comprising, a bridge aQbearingfjewe-l' fixed nsaldbr dge, an operating piyotpurnaled; ,in said ewel, a plate attached toYthetop of the hridgeg a bare cap: jewello osely housed in said platefso as to abut the; fearingjjewel and the end. of aai'pivqtsj s ringiearried,hylsaidv plate and directly abutting the upper; endpfsa-id cap jewel.-

a In testimonyh that we claim the as-our joint invention, we'fliaye signed our names this third day of June Q 4 JOSEPH merg rs em;

PAUL ALBERT BRUN. 

